̽��ֱ�� of Cambridge - dogs

Dogs may be at risk from high levels of lead from shotgun pellets in raw pheasant dog food, study finds

cg605 — Wed, 03 May 2023 00:01:30 +0000

Lead is a toxic metal that negatively affects body systems of people and animals, with the nervous system being particularly sensitive. Although elevated levels of dietary lead are potentially damaging to animal health, lead shot can be legally used for hunting terrestrial gamebirds, like pheasants, in the UK. While most pheasants are eaten by people, some are used in petfood.

Cambridge researchers analysed 90 samples taken from three raw pheasant dog food products bought in the UK and found that 77% of samples had lead concentrations exceeding the maximum residue level (MRL) permitted in animal feed according to law. Mean lead concentrations of the three products were approximately 245, 135 and 49 times higher than the MRL.

̽��ֱ��results are published today in the journal Ambio.

“We were already aware that lead concentrations in pheasant meat sold for human consumption are often far higher than would be permitted in other meats like chicken, beef or pork” said lead author Professor Debbie Pain of Cambridge’s Zoology Department. “However, we were surprised to find that lead concentrations in raw pheasant dog food products were so much higher”

̽��ֱ��mean lead concentration in the raw pheasant dog food analysed was 34 times higher than that recently reported in pheasant meat sold for people to eat, which itself is considered to be too high. Researchers say this could be because raw pheasant meat is normally minced when used for dogfood whereas whole birds or pheasant breasts are generally sold for human consumption. Mincing may fragment lead shot, increasing the number of small lead particles in the meat and the potential for lead to be absorbed into the bloodstream.

̽��ֱ��researchers say that dogs eating food with such high concentrations of lead, especially if they are fed on it frequently or as their main diet, are at risk of harm to their health. Puppies are particularly vulnerable both because young animals tend to absorb more of the lead they swallow than full-grown animals, and the developing nervous system is particularly affected by lead.

̽��ֱ��scientists tested five pheasant-based dog food products. Three of these were raw meat products, one was a dried pheasant and partridge product, and one was a processed tinned pheasant and goose-based product. Three equivalent chicken-based petfood products (raw meat, dried and processed) were also assessed.

In addition to the raw pheasant dog food, levels of lead above the MRL were identified in some samples of the dried pheasant-based product, although the mean concentration was far lower than in the raw products. None of the samples from the chicken-based products or the tinned pheasant and goose-based product contained unacceptable levels of lead.

̽��ֱ��popularity of raw meat diets for pets is increasing across the UK – a nation which is home to an estimated 13 million dogs and 12 million cats. ̽��ֱ��researchers found that raw dog food including pheasant meat was widely available in the UK. Raw pheasant pet food was sold by 34% of the 50 online raw pet food suppliers they checked – 71% of these stated that the meat may contain shot.

“ ̽��ֱ��fact that most samples from three randomly sampled raw pheasant pet food products had very high lead concentrations, and that our recent research on shot types used to kill pheasants found that 94% are shot with lead, suggests that this is a far broader issue than for just these three products,” said co-author Professor Rhys Green. “However, some producers may source pheasants that have not been shot with lead, and owners could ask about this when buying pet food.”

̽��ֱ��study of shot types in pheasants sold for human consumption is part of a body of research assessing the effectiveness of a voluntary ban in the UK on lead shotgun ammunition to shoot wild quarry, which is being phased in over a five-year period from February 2020. Nine major shooting organisations committed to this, for sustainability reasons, considering wildlife, the environment and also to ensure a market for the healthiest game products.

Cambridge scientists have consistently found compliance with the voluntary ban to be low, which is in line with other studies investigating other voluntary bans. However, a total ban in Denmark has been shown to be very effective.

A ban on the sale and use of lead gunshot, along with restrictions on lead bullets, is currently being considered under the UK REACH Chemicals Regulation.

̽��ֱ��analytical costs of this research were funded by Wild Justice.

D. Pain, R. E. Green, N. Bates, M. Guiu, M. A. Taggart, Lead concentrations in commercial dogfood containing pheasant in the UK, Ambio. DOI: 10.1007/s13280-023-01856-x

Researchers tested samples of raw pheasant dog food and discovered that the majority contained high levels of lead that could put dogs’ health at risk if they eat it frequently.

24K-Production / iStock / Getty Images Plus

Dog eating raw meat

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Preventing genetic diseases in dogs, our best friends

cg605 — Thu, 20 Apr 2023 11:46:19 +0000

How genetics and DNA testing can pave the way for more puppies to be born free from hereditary illnesses.

Gone to the dogs

zs332 — Mon, 24 May 2021 23:00:00 +0000

A story of finding unexpected companionship at the site of the worst nuclear accident in history, Chernobyl.

̽��ֱ��curious tale of the cancer ‘parasite’ that sailed the seas

cjb250 — Thu, 01 Aug 2019 18:48:46 +0000

A contagious canine cancer that conquered the world by spreading between dogs during mating likely arose around 6,000 years ago in Asia and spread around the globe through maritime activities.

Scheme launched to improve health of French Bulldogs, Pugs and Bulldogs

cjb250 — Mon, 04 Feb 2019 15:53:55 +0000

Developed by the ̽��ֱ�� of Cambridge and funded by the Kennel Club Charitable Trust, the new Respiratory Function Grading Scheme assesses dogs for the presence and severity of a breathing problem known as BOAS (Brachycephalic Obstructive Airway Syndrome). ̽��ֱ��scheme is currently available for the Pug, French Bulldog and Bulldog, and has the potential to improve the health and welfare of these breeds for generations to come.

Dogs with a flat, wide shaped head are said to be brachycephalic (‘brachy’ meaning short, and ‘cephalic’, meaning head). ̽��ֱ��soft tissue in the nose and throat of some brachycephalic dogs may be excessive for the airways, partially obstructing the airway and making it difficult for them to breathe normally and causing heavy panting or noisy breathing. This condition is known as BOAS and is a progressive disorder that can impair a dog’s ability to exercise, play, eat and sleep.

̽��ֱ��assessment, which can now be carried out by a number of specially trained assessors located across the UK involves listening to the dog’s airway both before and after an exercise tolerance test. Assessors then use a pre-defined protocol to grade the dog from zero to three. Dogs graded as zero are free of respiratory signs of BOAS, while dogs graded as three will show severe respiratory signs of BOAS, indicating that further veterinary examination is advised. ̽��ֱ��scheme issues guidance that dogs graded three should not be bred from.

These grades will be recorded on the Kennel Club’s database and published in the Breed Records Supplement, on the dog’s registration certificate, and on the Kennel Club Health Test Results Finder and Health webpages. ̽��ֱ��BOAS Scheme will be supported by guidelines for breeders, which enable them to understand the grade for their dogs in terms of risk when considering potential matings.

Speaking at the inaugural launch event, Bill Lambert, Senior Health and Welfare Manager at the Kennel Club said: “ ̽��ֱ��high demand for these breeds, combined with the already recognised health problems has made brachycephalic health and welfare one of the most pressing canine issues in the UK, and one of the Kennel Club’s top priorities. We’re proud to have been able to fund and develop this important scheme with the ̽��ֱ�� of Cambridge and continue to support further research into BOAS, together with the other steps we are taking to improve the health of future generations of these breeds.”

“Launching the BOAS Scheme is a huge step in the right direction to improve the health of these brachycephalic dogs and protect the future of these much-loved breeds. It will enable vets to identify dogs at risk of BOAS, provide breeders and owners with the best available information and advice to make informed decisions and inform ongoing research into the condition.

Dr Jane Ladlow, Royal College and European Specialist in Small Animal Surgery at the ̽��ֱ�� of Cambridge, said: “ ̽��ֱ��way that BOAS is inherited is very complex and so not always entirely predictable. We are researching the genetics of this condition but it is likely to take a few years before we have a viable genetics test. We have realised over the last few years how useful the functional grading scheme is in determining disease severity and it reflects the initial genetic data we have.

“ ̽��ֱ��scheme is a vital tool to help advise all owners if their dog is affected by BOAS and gives guidance to breeders to lower the risk of producing affected puppies. It also, crucially, facilitates important data collection and enables researchers to monitor the frequency of the condition and progress in the breed affected, which will inform ongoing research, for the overall improvement of relevant breeds.

Dr Ladlow and colleagues will be working with the Kennel Club and other organisations dedicated to improving brachycephalic dog health across the board through promoting the scheme and engaging vets, breeders and puppy-buyers to raise awareness and understanding of BOAS.

Adapted from a press release from the Kennel Club.

A new screening scheme aims to provide breeders of French Bulldogs, Pugs and Bulldogs with more information about the health of their dogs, helping them reduce the risk of breeding puppies with potentially serious breathing problems.

̽��ֱ��scheme is a vital tool to help advise all owners if their dog is affected by [breathing difficulties] and gives guidance to breeders to lower the risk of producing affected puppies

Jane Ladlow

GLady

French bulldog

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Ancient American dogs almost completely wiped out by arrival of European breeds

cjb250 — Thu, 05 Jul 2018 18:00:52 +0000

But one close relative of these native dogs lives on in an unexpected place – as a transmissible cancer whose genome is that of the original dog in which it appeared, but which has since spread throughout the world.

Using genetic information from 71 archaeological dog remains from North America and Siberia, an international team led by researchers at the ̽��ֱ�� of Oxford, ̽��ֱ�� of Cambridge, Queen Mary ̽��ֱ�� of London, and Durham ̽��ֱ�� showed that ‘native’ (or ‘pre-contact’) American dogs, which arrived alongside people over 10,000 years ago and dispersed throughout North and South America, possessed genetic signatures unlike dogs found anywhere else in the world.

Comparison of ancient and modern American dog genomes, however, demonstrated that these pre-contact American dogs rapidly disappeared following the arrival of Europeans and left little to no trace in modern American dogs.

Senior lead author Dr Laurent Frantz from Queen Mary ̽��ֱ�� and the Palaeogenomics & Bio-Archaeology Research Network (Palaeo-BARN) at Oxford said: “It is fascinating that a population of dogs that inhabited many parts of the Americas for thousands of years, and that was an integral part of so many Native American cultures, could have disappeared so rapidly. Their near-total disappearance is likely due to the combined effects of disease, cultural persecution and biological changes starting with the arrival of Europeans.”

Professor Greger Larson, Director of the Palaeo-BARN at Oxford and senior author of the study, said: “This study demonstrates that the history of humans is mirrored in our domestic animals. People in Europe and the Americas were genetically distinct, and so were their dogs. And just as indigenous people in the Americas were displaced by European colonists, the same is true of their dogs.”

By comparing the ancient and modern genomes, the researchers confirmed that the earliest American dogs were not descended from North American wolves, but likely originated in Siberia, crossing into the Americas during early human migrations.

Lead archaeologist Dr Angela Perri from Durham ̽��ֱ��, co-first author on the study, added: “Archaeological evidence has long suggested that ancient dogs had a dynamic history in the Americas, but the fate of these pre-contact dogs and their relationship to modern American dog populations was largely unknown. Our study confirms that they likely originated in Siberia, crossing the Bering Strait during initial human migrations.”

“In fact, we now know that the modern American dogs beloved worldwide, such as Labradors and Chihuahuas, are largely descended from Eurasian breeds, introduced to the Americas between the 15th and 20th centuries.”

Intriguingly, the study revealed a close link between the genomes of the pre-contact dogs, as the researchers refer to them, and those derived from canine transmissible venereal tumours (CTVT). CTVT is a contagious genital cancer that is spread between dogs by the transfer of living cancer cells during mating. CTVT originated from the cells of a single dog, known as the ‘CTVT founder dog’, that lived several thousand years ago. Remarkably, the research revealed that the dog that first spawned CTVT was closely related to American pre-contact dogs. Overall the results indicate that this cancer, now found worldwide, possesses a genome that is the last remaining vestige of the dog population that was once found all across the Americas.

“It’s quite incredible to think that possibly the only survivor of a lost dog lineage is a tumour that can spread between dogs as an infection,” added Maire Ní Leathlobhair, co-first author, from the Department of Veterinary Medicine at the ̽��ֱ�� of Cambridge. “Although this cancer’s DNA has mutated over the years, it is still essentially the DNA of that original founder dog from many thousands of years ago.”

Co-author and zooarchaeologist Professor Keith Dobney from the ̽��ֱ�� of Liverpool, who co-directs the dog domestication project with Professor Larson added “This is yet another new and exciting finding from our combined genetic and archaeological research, which continues to challenge and illuminate our understanding of the history of the first and most iconic domestic animal.”

̽��ֱ��research was largely funded by Wellcome, the Natural Environment Research Council, and the European Research Council.

Reference
Ní Leathlobhair, M, Perri, AR, Irving-Pease, EK, Witt, KE, Linderholm, A, et al. ̽��ֱ��Evolutionary History of Dogs in the Americas. Science; 6 July 2018; DOI: 10.1126/science.aao4776

̽��ֱ��arrival of Europeans to the Americas, beginning in the 15th century, all but wiped out the dogs that had lived alongside native people on the continent for thousands of years, according to new research published today in Science.

It’s quite incredible to think that possibly the only survivor of a lost dog lineage is a tumour that can spread between dogs as an infection

Maire Ní Leathlobhair

Del Baston (courtesy of the Center for American Archeology)

Ancient dog burial

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No simple way of predicting breathing difficulties in pugs, French bulldogs and bulldogs from external features

sjr81 — Tue, 01 Aug 2017 18:00:17 +0000

̽��ֱ��findings have implications for attempts to ‘breed out’ this potentially life-threatening condition.

Pugs and bulldogs have become popular breeds in recent years – the French bulldog is set to become the UK's most popular canine, according to the Kennel Club. However, a significant proportion are affected by a condition known as Brachycephalic Obstructive Airway Syndrome (BOAS) related to their head structure.

Studies suggest that for over half of such dogs, BOAS may lead to health problems, causing not just snoring but also difficulty exercising and potentially overheating. It can even prove life-threating. But as symptoms often do not arise until after the dog has begun breeding, veterinary scientists have been searching for markers that can predict whether a dog is likely to develop breathing difficulties – and hence potentially help breed out the condition.

A study in 2015 led by researchers at the Royal Veterinary College, ̽��ֱ�� of London, working across many breeds suggested that dogs whose muzzles comprised less than half their cranial lengths and dogs with thicker neck girths were at increased risk of BOAS. However, a new study carried out by researchers at the Department of Veterinary Medicine, ̽��ֱ�� of Cambridge, and published today in the journal PLOS ONE, suggests that these measures applied to individual breeds are not dependable for this purpose.

̽��ֱ��Cambridge researchers took external measurements of features of head and neck shape, and of the external appearance of nostrils, together with measurements of body size and body condition score (an approximation to the degree of fatness/obesity) in just over 600 pugs, bulldogs and French bulldogs, the most numerous breeds that show this problem. Each of the dogs had also been graded objectively for respiratory function.

̽��ֱ��team found that while the external head measurements did have some predictive value for respiratory function, the relationship was not strong, and the measurements that showed the best predictive relationship to BOAS differed between breeds. They were unable to reproduce conclusively the findings from the previous study by the Royal Veterinary College in any breed.

“It can be incredibly difficult to take measurements such as distance between eyes or length of nose accurately, even for experienced vets, as the dogs don’t keep still,” says Dr Jane Ladlow, joint lead author. “This may explain why it is so difficult to replicate the findings of the previous study or find any conclusive markers in our own.”

Neck girth was a slightly more reproducible measurement, and larger neck girth in comparison to chest girth or neck length was associated with disease in the bulldogs and French bulldogs. In male bulldogs, neck girth showed a close enough association with disease to give moderately good predictive accuracy for the presence of clinically significant BOAS.

̽��ֱ��best measure identified by the Cambridge team was the degree of nostril opening, which proved a moderately good predictor of the presence and severity of BOAS in pugs and French bulldogs, and was also a useful marker for disease in bulldogs.

Altogether the variables measured, when combined, gave an 80% accuracy in predicting whether or not dogs will have BOAS, the difficulty of taking some of the measurements accurately, and the need to make multiple measurements and combine them in order to produce a prediction means that the researchers would not recommend using them as a guide to breeding.

Dr Nai-Chieh Liu, first author of the study, says: “Breeding for open nostrils is probably the best simple way to improve these breeds. Dog breeders should also avoid using dogs with extremely short muzzles, wide faces, and thick necks. These traits are all associated with increased risk of having BOAS.”

Joint lead author Dr David Sargan adds “At this moment there is no conclusive way of predicting whether any individual pug or bulldog will develop breathing difficulties, so we are now looking for genetic tests that may help breeders get rid of BOAS more rapidly.

“ ̽��ֱ��best advice we can give to owners of short-nosed dogs is to make sure you get your dog checked annually for any potential difficulties in breathing, even if you have not yourself observed any in your dog, and to keep your dog fit and not let it get fat.”

As many as a half of all short-nosed dogs such as pugs, French bulldogs and bulldogs experience breathing difficulties related to their facial structure. However, research published today by the ̽��ֱ�� of Cambridge suggests that there is no way to accurately predict from visible features whether an apparently healthy pug or French bulldog will go on to develop breathing difficulties.

Dog breeders should also avoid using dogs with extremely short muzzles, wide faces, and thick necks.

Nai-Chieh Liu

LW Yang

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Opinion: How to save inbred, short-faced dogs such as pugs and bulldogs from poor health

Anonymous — Tue, 02 Aug 2016 14:23:06 +0000

Short-faced dogs such as pugs, bulldogs (known as English bulldogs in the US) and French bulldogs are among the cutest pets out there – they’re the very reverse of the wolves they descended from. Over the last few years these breeds have become increasingly common, partly thanks to advertising and their popularity among celebrities. In fact all three breeds are now in Britain’s top ten favourite dogs.

But these dogs are the result of an amazing transformation in appearance and temperament caused by selective breeding, which has come at quite a cost to the dogs' health. Around half of them have breathing problems that sometimes lead to overheating, exercise intolerance and sleep apnoea. Their large heads and narrow pelvises also cause problems in giving birth (forcing Caesarean sections for many if not most) and their skin folds can become infected. Their exposed eyes are also vulnerable to damage, with about 15% suffering prolapsed third eyelids and many having other types of eye damage. Quite a number of dogs in several of the breeds also succumb to back or hip problems.

So research geneticists have started to look at ways to reduce the intrinsic health problems of these breeds. A recent investigation of genetic variation in bulldogs showed that all the individuals examined had little genetic diversity in either paternal or maternal lines. ̽��ֱ��same was true for the diversity of some types of immune system genes, so that the ability of these bulldogs to respond to pathogens may be reduced, which may potentially also be connected to common allergies in this breed. ̽��ֱ��authors argued that the breed’s health could only be restored by breeding dogs with other breeds, rather than preserving the breed in its current closed state.

With colleagues including Jane Ladlow, Lajos Kalmar and Nai-chieh Liu, I have been doing both genetic and clinical analyses of bulldogs and other short-faced breeds. Working with breeders of bulldogs, we investigated the respiratory distress that many of these dogs suffer from. We started by developing a computer algorithm to interpret breathing traces taken from dogs at rest, allowing us to objectively identify the disease and quantify variation between individuals. This analysis, together with collection of DNA samples from the studied dogs, opened the way for accurate genetic analyses of the respiratory disease. On the way, we also gained information on the genetic health of the breeds we studied as a whole.

Our findings agree with those of the new study in suggesting that the best way of breeding back to a less extreme skull shape would be to introduce dogs from outside the current breed registers. This is likely to be true of many other aspects of conformation and temperament. And we would agree that the extreme changes in appearance (such as the excessive skin rolls in these breeds) do account for many of their disease problems.

An alternative to outbreeding?

Fortunately not all short-faced dogs suffer from the respiratory disorder and although our research is not yet complete, we now have pretty strong evidence that there are still multiple genetic variations between those that do and those that don’t. But we do not know whether this is also true for other aspects of conformation and appearance-related conditions.

A bulldog being assessed by respiratory trace recording in a barometric chamber. Traces from another dog on the right. Author provided

We believe that the swiftest way to remove these diseases would be to outbreed to a dog type that does not have the features that cause the health problems typical of these breeds.

Over the last few years groups such as the (now disbanded) Advisory Council on the Welfare Aspects of Dog Breeding, the RSPCA, a number of dog welfare charities and the Associate Parliamentary Group on Animal Welfare have offered a lot of advice about the health problems of these dogs in an attempt to reduce their popularity. Yet the kind of expensive advertising campaign that could really reach the public has been lacking.

An additional problem is that most breeders reject the introduction of genes from outside their breed. They fear the breed will “be contaminated”, that new diseases will be introduced and that the breed will lose its character or change in temperament. There appears to be no likelihood of legislation to compel breeders to outbreed on welfare grounds.

But with the help of our research it may be possible to breed for healthier dogs using the existing genetic variation within the breed (in addition to contributions from crosses outside the breed if necessary and if they can be made acceptable to breeders). If within-breed crosses to reduce disease do prove practical, this will probably be a slower route to reduce the disease burden for an individual offspring than an outcross-breed. However, the advantage is that within-breed crosses are likely to be widely accepted by dog breeders and so it may prove a quicker way of moving the whole population forward towards better breed health.

David Sargan, Senior Lecturer in Molecular Pathology at the Department of Veterinary Medicine, ̽��ֱ�� of Cambridge

This article was originally published on ̽��ֱ��Conversation. Read the original article.

̽��ֱ��opinions expressed in this article are those of the individual author(s) and do not represent the views of the ̽��ֱ�� of Cambridge.

David Sargan (Department of Veterinary Medicine) discusses the health implications of breeding the perfect pets.

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